Voltage-regulating apparatus



Dec. zsgmzs. 5 1,612,370

' R. M. GlLSON VOLTAGE REGULATING APPARATUS Filed May 26, 1923 INVENTOR;

Patented Dec. 28, 1926.

ROBERT M". GELSGN, 0 PITTEIBUEG S'VTITCH SIGNAL CDI'EPANY, OF S'WISSVALE, PEI:

PENN SYLVANIA.

VOLTAGE-REGULATII-TG- Application filed Ivlay 26,

lily invention relates to voltage regulating apparatus, that is, apparatus adapted for use between a source of energy and an applied to said device.

I will describe one form of apparatus embodying my invention, and will then point out the novel features thereof in claims.

The accoinp; iying drawing is a diagramu'ia'tic View showing one form and arrangement of apparatus embodying my invention Referring to the drawing, the reference characters 1 and l. designate the track rails of a railroad over which trafiic normally moves in the direction indicated by the arrow. These rails are divided, by means of insulated joints 2, into a plurality of track sections of which only one section l\.-B is shown in the drawing. This sec tion A-B is provided with a source of track circuit current here shown as a track transformer G having its secondary winding 5 connected across the rails adjacent the exit end of the section. Interposed between one rail 1 of section A-B and the secondary 5 of track transformer C is an impedance 6 one function of which is to limit the output of the transformer when its terminals are short-circuited by the wheels and axles of a train. The primary winding l of track transformer C is constantly supplied with alternating current from some suitable source such as an alternator G over line wires 3 and 3*.

Located adjacent the entrance end of the section is a track relay D comprising two windings 7 and 8 and a rotor 9. One winding 8, is constantly supplied with alternating current from alternator G over line wires 3 and 3 The remaining winding 7 of relay D is connected across the rails of section AB adjacent the entrance end of the section. The position of rotor 9 of relay D is therefore responsive to the presence or absence of track circuit current in the rails of section AB and may be utilized to control train governing apparatus in any desired manner by means of contacts such as contact 10. v

t is clear that there will be a certain amount of current leakage between the rails 1 and 1 and that the amount of this leakage will depend upon the resistance of the track ballast which varies with weather con- -v' ...x.. Y consuming LlQvLCO ioi ieguiating tire ARAT'QTEL 1923. Serial No. G l-1,503.

ditions, etc. Since the voltage at the secondary 5 of track transformer C is constant, it follows that there is a corresponding variation in the voltage applied to the terminals of winding 7 of relay D. lhis is undesirable, and to prevent its occurrence I iuterpose between winding '4" and one rail 1 of the section, a device here shown as an iron core reactor coil so. designed that its flux density is normally very low. The device E may, however, be tungsten ballast lamp, or any other device so arranged that iucreased currents through the device will increase the impedance thereof. I also connect across the rails of the section adjacent the relay D, a device F, here shown as an iron core reactor so designed that at normal voltages, the flux density in the core is near saturation. Any other apparatus so arranged that an increased current through the device will result in a decreased impedance may be substituted for this reactor.

The parts are so proportioned that under the worst conditions, that is, when leakage from rail to rail is maximum, the voltage applied at terminals a and Z) of winding 7 of relay D is suflicient to energize the relay. Now if the leakage bet-ween rails decreases, as by drying out of the ballast, or some other reason, the increased voltage across the rails at point A causes a larger current to pass through device F, thus decreasing the impedance of this device. As a result a larger proportion of current is taken by this device. At the same time the current through device E and winding 7 tends to increase, though in a less degree than the increase in track voltage. As a result the impedance of device E increases and the current increase through the relay is thus still further limited.

It will thus be plain that due to the action of devices i and E, a given increase in voltage between rails 1 and 1 causes a very much smaller increase in the voltage between terminals or, and b of relay D than if these devices were not provided, and that the relay is thereby protected from excessive voltages.

Although I have herein shown and described only one form of regulating: apparatus embodying my invention, it is understood that various changes and modiiications may be made therein within the scope of the appended claims without detil) parting from the spirit and scope of my invention.

Having thus described my invention, What I claim is:

1. In combination, a section of railway track, a source of energy connected With the rails, a track relay also connected With the rails, an iron core reactor connected in parallel with said relay and normally having a core flux density of approximately saturation, and a second iron core reactor interposed between said relay and said first reactor and normally having a very low core flux density.

2. In combination, a section of railway track, a source of energy connected With the rails, a track relay also connected with the rails, means connected in series With said relay and having the characteristic of increasing its impedance in response to increases in the current therethrough and other means connected across said relay and said first means and responsive to an increase in volt age to shunt an increased amount of current away from such relay and such first mentioned means.

In testimony whereof I affix my signature.

ROBERT M. GILSON. 

